intel/fs: Add an UNDEF instruction to avoid excess live ranges

[mesa.git] / src / intel / compiler / brw_fs_builder.h

diff --git a/src/intel/compiler/brw_fs_builder.h b/src/intel/compiler/brw_fs_builder.h
index c50af4c1f55053b35cf94b46ba33d3121e69ef06..9655c2ef55477625e3710d4526f98882f7b8adc7 100644 (file)
--- a/src/intel/compiler/brw_fs_builder.h
+++ b/src/intel/compiler/brw_fs_builder.h
@@ -426,6 +426,21 @@ namespace brw {
          return src_reg(component(dst, 0));
       }
 
+      src_reg
+      move_to_vgrf(const src_reg &src, unsigned num_components) const
+      {
+         src_reg *const src_comps = new src_reg[num_components];
+         for (unsigned i = 0; i < num_components; i++)
+            src_comps[i] = offset(src, dispatch_width(), i);
+
+         const dst_reg dst = vgrf(src.type, num_components);
+         LOAD_PAYLOAD(dst, src_comps, num_components, 0);
+
+         delete[] src_comps;
+
+         return src_reg(dst);
+      }
+
       void
       emit_scan(enum opcode opcode, const dst_reg &tmp,
                 unsigned cluster_size, brw_conditional_mod mod) const
@@ -691,6 +706,17 @@ namespace brw {
          return inst;
       }
 
+      instruction *
+      UNDEF(const dst_reg &dst) const
+      {
+         assert(dst.file == VGRF);
+         instruction *inst = emit(SHADER_OPCODE_UNDEF,
+                                  retype(dst, BRW_REGISTER_TYPE_UD));
+         inst->size_written = shader->alloc.sizes[dst.nr] * REG_SIZE;
+
+         return inst;
+      }
+
       backend_shader *shader;
 
    private:
@@ -718,13 +744,26 @@ namespace brw {
       src_reg
       fix_3src_operand(const src_reg &src) const
       {
-         if (src.file == VGRF || src.file == UNIFORM || src.stride > 1) {
+         switch (src.file) {
+         case FIXED_GRF:
+            /* FINISHME: Could handle scalar region, other stride=1 regions */
+            if (src.vstride != BRW_VERTICAL_STRIDE_8 ||
+                src.width != BRW_WIDTH_8 ||
+                src.hstride != BRW_HORIZONTAL_STRIDE_1)
+               break;
+            /* fallthrough */
+         case ATTR:
+         case VGRF:
+         case UNIFORM:
+         case IMM:
             return src;
-         } else {
-            dst_reg expanded = vgrf(src.type);
-            MOV(expanded, src);
-            return expanded;
+         default:
+            break;
          }
+
+         dst_reg expanded = vgrf(src.type);
+         MOV(expanded, src);
+         return expanded;
       }
 
       /**